Dengue 2 virus envelope protein expressed by a recombinant vaccinia virus fails to protect monkeys against dengue.

A cDNA copy of the dengue (DEN) 2 virus genome region encoding the virion capsid, membrane and envelope structural proteins has been inserted into vaccinia virus (VV) DNA under the control of its 11K late promoter. The DEN-2 envelope protein was expressed and processed in cells infected with the VV recombinant (VV/D2S). No DEN-2 virus antibody response was detected in mice, hamsters or monkeys vaccinated with VV/D2S. Furthermore, a viraemia was observed in recombinant-vaccinated monkeys after challenge with infectious DEN-2 virus.